DE2623482C2 - Process for the production of a crystalline aluminum oxide for polishing, lapping and grinding media - Google Patents
Process for the production of a crystalline aluminum oxide for polishing, lapping and grinding mediaInfo
- Publication number
- DE2623482C2 DE2623482C2 DE2623482A DE2623482A DE2623482C2 DE 2623482 C2 DE2623482 C2 DE 2623482C2 DE 2623482 A DE2623482 A DE 2623482A DE 2623482 A DE2623482 A DE 2623482A DE 2623482 C2 DE2623482 C2 DE 2623482C2
- Authority
- DE
- Germany
- Prior art keywords
- aluminum oxide
- weight
- production
- lapping
- polishing
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 title claims description 18
- 238000000227 grinding Methods 0.000 title claims description 6
- 238000005498 polishing Methods 0.000 title claims description 3
- 238000000034 method Methods 0.000 title description 10
- 238000004519 manufacturing process Methods 0.000 title description 6
- 239000013078 crystal Substances 0.000 claims description 10
- 229910052720 vanadium Inorganic materials 0.000 claims description 3
- 229910052708 sodium Inorganic materials 0.000 claims description 2
- 239000011734 sodium Substances 0.000 description 10
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 8
- 238000001354 calcination Methods 0.000 description 7
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 description 7
- WNROFYMDJYEPJX-UHFFFAOYSA-K aluminium hydroxide Chemical compound [OH-].[OH-].[OH-].[Al+3] WNROFYMDJYEPJX-UHFFFAOYSA-K 0.000 description 6
- 150000002222 fluorine compounds Chemical class 0.000 description 6
- 239000000203 mixture Substances 0.000 description 6
- 150000003839 salts Chemical class 0.000 description 5
- 150000003681 vanadium Chemical class 0.000 description 5
- PNEYBMLMFCGWSK-UHFFFAOYSA-N Alumina Chemical class [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 4
- 238000004131 Bayer process Methods 0.000 description 4
- ANBBXQWFNXMHLD-UHFFFAOYSA-N aluminum;sodium;oxygen(2-) Chemical compound [O-2].[O-2].[Na+].[Al+3] ANBBXQWFNXMHLD-UHFFFAOYSA-N 0.000 description 4
- 229910001388 sodium aluminate Inorganic materials 0.000 description 4
- 229910052731 fluorine Inorganic materials 0.000 description 3
- 239000011164 primary particle Substances 0.000 description 3
- 229910016569 AlF 3 Inorganic materials 0.000 description 2
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 description 2
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 2
- 238000002425 crystallisation Methods 0.000 description 2
- 230000008025 crystallization Effects 0.000 description 2
- 150000002221 fluorine Chemical class 0.000 description 2
- 239000011737 fluorine Substances 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- IRPGOXJVTQTAAN-UHFFFAOYSA-N 2,2,3,3,3-pentafluoropropanal Chemical compound FC(F)(F)C(F)(F)C=O IRPGOXJVTQTAAN-UHFFFAOYSA-N 0.000 description 1
- -1 AlF 3 Chemical class 0.000 description 1
- KLZUFWVZNOTSEM-UHFFFAOYSA-K Aluminum fluoride Inorganic materials F[Al](F)F KLZUFWVZNOTSEM-UHFFFAOYSA-K 0.000 description 1
- 229910004261 CaF 2 Inorganic materials 0.000 description 1
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 1
- 150000001495 arsenic compounds Chemical class 0.000 description 1
- 229910001570 bauxite Inorganic materials 0.000 description 1
- 239000006227 byproduct Substances 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 229910001679 gibbsite Inorganic materials 0.000 description 1
- 229940093920 gynecological arsenic compound Drugs 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 229910052698 phosphorus Inorganic materials 0.000 description 1
- 239000011574 phosphorus Substances 0.000 description 1
- 229910000029 sodium carbonate Inorganic materials 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000011573 trace mineral Substances 0.000 description 1
- 235000013619 trace mineral Nutrition 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
- GPPXJZIENCGNKB-UHFFFAOYSA-N vanadium Chemical compound [V]#[V] GPPXJZIENCGNKB-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K3/00—Materials not provided for elsewhere
- C09K3/14—Anti-slip materials; Abrasives
- C09K3/1409—Abrasive particles per se
- C09K3/1418—Abrasive particles per se obtained by division of a mass agglomerated by sintering
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
- C01F7/00—Compounds of aluminium
- C01F7/02—Aluminium oxide; Aluminium hydroxide; Aluminates
- C01F7/44—Dehydration of aluminium oxide or hydroxide, i.e. all conversions of one form into another involving a loss of water
- C01F7/441—Dehydration of aluminium oxide or hydroxide, i.e. all conversions of one form into another involving a loss of water by calcination
- C01F7/442—Dehydration of aluminium oxide or hydroxide, i.e. all conversions of one form into another involving a loss of water by calcination in presence of a calcination additive
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/01—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics
- C04B35/10—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on oxide ceramics based on aluminium oxide
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/60—Particles characterised by their size
- C01P2004/61—Micrometer sized, i.e. from 1-100 micrometer
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/60—Particles characterised by their size
- C01P2004/62—Submicrometer sized, i.e. from 0.1-1 micrometer
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/12—Surface area
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Ceramic Engineering (AREA)
- Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Inorganic Chemistry (AREA)
- Manufacturing & Machinery (AREA)
- Structural Engineering (AREA)
- Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
- Crystals, And After-Treatments Of Crystals (AREA)
Description
enthalten.contain.
2. Verfahren zur Herstellung von kristallinem Aluminiumoxid nach Anspruch 1, durch Kalzination von V2O5, P2O5 und Na2O enthaltendem Aluminiumhydroxid aus dem Bayer-Prozeß in Gegenwart von Fluorverbindungen, dadurch gekennzeichnet, daß ein Aluminiumhydroxid, das2. A method for the production of crystalline aluminum oxide according to claim 1, by calcination of V 2 O 5 , P 2 O 5 and Na 2 O containing aluminum hydroxide from the Bayer process in the presence of fluorine compounds, characterized in that an aluminum hydroxide, the
aufweist, in Gegenwart von mindestens einer Fluorverbindung
kalziniert wird.having, in the presence of at least one fluorine compound
is calcined.
3. Verfahren nach Anspruch 2, dadurch gekennzeichnet, daß in Gegenwart von 0,001 bis 0,1 Gew.-96 einer Fluorverbindung, bezogen auf AI2O5, kalziniert wird.3. The method according to claim 2, characterized in that in the presence of 0.001 to 0.1 wt-96 of a fluorine compound, based on Al 2 O 5 , is calcined.
4. Verfahren nach den Ansprüchen 2 und 3, dadurch gekennzeichnet, daß bei Temperaturen von 1100 bis 1300° C kalziniert wird.4. Process according to claims 2 and 3, characterized in that at temperatures from 1100 to 1300 ° C is calcined.
Gegenstand der vorliegenden Erfindung ist ein kristallines Aluminiumoxid für Polier-, Läpp- und Schleifmittel, sowie ein Verfahren zu seiner Herstellung.The present invention relates to a crystalline aluminum oxide for polishing, lapping and grinding agents, and a method for its production.
Technisches Aluminiumoxid wird üblicherweise durch Erhitzen (Kalzination) von Aluminiumhydroxid (Hydrargillit) im Drehrohrofen oder Wirbelschichtofen bei Temperaturen um 11000C hergestellt. Das so herge-3S stellte Aluminiumoxid mit einem Glühverlust von 0,5 bis 196 setzt sich aus einem Gemisch von Übergangsoxiden der gamma-Al2Oj-Reihe und aus alpha-Al2Oj zusammen und ist charakterisiert durch eine spezifische Oberfläche von 5-30 m2/g. Die mittlere Primärteilchengröße, bestimmt nach der Methode von Eppendorf, bei der nach Aufmahlung des Aluminiumoxids mit Hilfe des Eppendorf-Fotometers die optische Dichte einer in Wasser aufgeschlämmten Aluminiumoxidprobe in Abhängigkeit von der Zeit gemessen und die hieraus resultierende Kornverteilung des Aluminiumoxides ermittelt wird, beträgt ca. 0,5-1 μΐη.Technical aluminum oxide is usually produced by heating (calcination) aluminum hydroxide (hydrargillite) in a rotary kiln or fluidized bed furnace at temperatures around 1100 ° C. The aluminum oxide produced in this way with a loss on ignition of 0.5 to 196 is composed of a mixture of transition oxides of the gamma-Al 2 Oj series and of alpha-Al 2 Oj and is characterized by a specific surface area of 5-30 m 2 / g. The mean primary particle size, determined according to the Eppendorf method, in which after grinding the aluminum oxide with the aid of the Eppendorf photometer the optical density of an aluminum oxide sample suspended in water is measured as a function of time and the resulting particle distribution of the aluminum oxide is determined, is approx. 0.5-1 μΐη.
Wird die Kalzlnations-Temperatur auf über 1200° C erhöht, bildet sich Aluminiumoxid in fast nur alpha-Modifikatlon, die spezifische Oberfläche verringert sich auf Werte von < 1 mVg und die mittlere Primärtell- -chengröße wächst auf ca. 3 μπι an.If the calcination temperature is increased to over 1200 ° C, aluminum oxide is formed in almost only alpha-modification, the specific surface area is reduced to values of <1 mVg and the mean primary cell -chen size grows to about 3 μm.
Es ist weiterhin bekannt, daß in Gegenwart von etwa 0,001-0,5 Gew.-96 eines Mineralisators Im Aufgabehydroxid,
z. B. in Gegenwart von Fluorsalzen wie AlF3, CaF2 oder Na3AlF6, bereits bei Temperaturen von ca.
HOO0C Aluminiumoxide der alpha-Modlflkation entstehen, deren spezifische Oberfläche mit 0,5 m2/g ebenfalls
klein ist. Die mittlere Primärkristallgröße derartiger Aluminiumoxide liegt bei ca. 6 μίτι. Höhere Temperaturen
und/oder größere Mengen der beispielhaft erwähnten Mineralisatoren beeinflussen die vorstehenden Kenngrößen
wie Modifikation, spezifische Oberfläche und mittlere Primärkristallgröße nur unwesentlich.
Für bestimmte Anwendungsgebiete beim Schleifen und LäppeT wird jedoch Aluminiumoxid mit einer mittleren
Primärkristallgröße von größer als 6 pm benötigt. Die Herstellung eines derartigen Aluminiumoxides 1st
somit Aufgabe der vorliegenden Erfindung.It is also known that in the presence of about 0.001-0.5% by weight of a mineralizer in the feed hydroxide, e.g. B. in the presence of fluorine salts such as AlF 3 , CaF 2 or Na 3 AlF 6 , already at temperatures of about HOO 0 C aluminum oxides of the alpha-Modlflkation are formed, the specific surface area of 0.5 m 2 / g is also small. The mean primary crystal size of such aluminum oxides is approximately 6 μm. Higher temperatures and / or larger amounts of the mineralizers mentioned by way of example only have an insignificant effect on the above parameters such as modification, specific surface area and mean primary crystal size.
For certain areas of application in grinding and lapping, however, aluminum oxide with an average primary crystal size of greater than 6 μm is required. The production of such an aluminum oxide is therefore an object of the present invention.
Überraschenderwelse hat sich gezeigt, daß kristallines Aluminiumoxid mit einer mittleren Primärkristallgröße
von 6-25, Insbesondere 8-16 μίτι durch Kalzination von V2O5, P2O5 und Na2O enthaltendem Alumlnlumhydroxid
aus dem Bayer-Prozeß In Gegenwart von Fluorverbindungen hergestellt werden kann.
Das Verfahren Ist dadurch gekennzeichnet, daß ein Aluminiumhydroxid, dasSurprisingly, it has been shown that crystalline aluminum oxide with an average primary crystal size of 6-25, in particular 8-16 μίτι by calcination of V 2 O 5 , P 2 O 5 and Na 2 O-containing aluminum hydroxide produced from the Bayer process in the presence of fluorine compounds can be.
The method is characterized in that an aluminum hydroxide, the
einen V2O5-Gehalt von
einen P2Os-Gehalt von
einen F-Gehalt vona V 2 O 5 content of
a P 2 O s content of
an F-content of
und einen Na2O-Gehalt vonand an Na 2 O content of
aufweist, in Gegenwart von mindestens einer Fluorverbindung kalziniert wird.is calcined in the presence of at least one fluorine compound.
Das Aluminiumhydroxid, das üblicherweise für die Kalzination von Aluminiumoxid eingesetzt wird, weist einen Al2O3-Gehalt von 65 Gew.-96 auf und enthält folgende Mengen an Spurenelementen:The aluminum hydroxide, which is usually used for the calcination of aluminum oxide, has an Al 2 O 3 content of 65% by weight and contains the following amounts of trace elements:
V2O5 < 0,005%, ζ. Β. 0,0003%V 2 O 5 <0.005%, ζ. Β. 0.0003%
P2O5 < 0,005%, ζ. B. 0,0004%P 2 O 5 <0.005%, ζ. B. 0.0004%
F < 0,01 %, ζ. B. 0,004-0,008%F <0.01%, ζ. B. 0.004-0.008%
Na2O < 0,6 %, ζ. B. 0,3-0,5%Na 2 O <0.6%, ζ. B. 0.3-0.5%
Dem Aufgabehydroxid müssen demnach zur Erreichung der vorgegebenen Konzentrationen V2Os, P:OS und Na2O, gegebenenfalls auch Fluor enthaltende Verbindungen zugesetzt werden.Accordingly, in order to achieve the specified concentrations V 2 Os, P: O S and Na 2 O, fluorine-containing compounds may also have to be added to the feed hydroxide.
Erfindungsgemäß erfolgt die Dotierung mit dem beim Bayer-Prozeß als Nebenprodukt anfallendem Vanadinsalz. Unter Vanadinsalz werden hier die in vielen Tonerdefabriken aus der konzentrierten Natrlumaluminatlauge ausgeschiedenen Fremdsalze verstanden, die neben sehr viel Natriumcarbonat wechselnde Mengen an Vanadin,-Phosphor-, Fluor- und Arsenverbindungen enthalten. Die Fremdsalze reichern sich bekanntlich in den im Bayer-Prozeß umlaufenden Natriumaluminatlaugen an und werden entweder durch CaO-Zusatz gemeinsam mit dem Rotschlamm aus den Natriumaluminatlaugen abgetrennt oder durch ein spezielles Kristallisationsverfahren aus der Lauge bis unterhalb der Sättigungsgrenze ausgeschieden.According to the invention, the doping takes place with the vanadium salt obtained as a by-product in the Bayer process. Vanadium salt is used here in many alumina factories from the concentrated sodium aluminate liquor understood foreign salts excreted, which in addition to a lot of sodium carbonate, varying amounts of vanadium, phosphorus, Contain fluorine and arsenic compounds. As is known, the foreign salts accumulate in the im Bayer process circulating sodium aluminate and are either by adding CaO together with separated from the red mud from the sodium aluminate liquor or through a special crystallization process excreted from the liquor to below the saturation limit.
Die Zusammensetzung des sogenannten Vanadinsalzes schwankt sehr stark. In Abhängigkeit von Betriebsführung und Provenienz des Bauxits kann ein solches Salz neben 45,796 Kristallwasser beispielsweise 1,8,0,5 oder 3,6 Gew.-% As2O3, 5,2,2 oder 10 Gew.-% V2O5, 12, 6 oder 20 Gew.-% P2O5, 1,9, 1 oder 3,5 Gew.-% F und 3,53, 10 oder 15 Gew.-% CO2, enthalten. Eine Folge der vorerwähnten Schwankungen ist, daß mengenmäßige Angaben hinsichtlich des eingesetzten Vanadinsalzes nur gemacht werden können, wenn die Zusammensetzung des Salzes bekannt ist.The composition of the so-called vanadium salt fluctuates very strongly. Depending on the management and provenance of the bauxite, such a salt can contain, in addition to 45.796 water of crystallization, for example 1.8, 0.5 or 3.6% by weight As 2 O 3 , 5.2.2 or 10% by weight V 2 O 5 , 12, 6 or 20% by weight P 2 O 5 , 1.9, 1 or 3.5% by weight F and 3.53, 10 or 15% by weight CO 2 . One consequence of the fluctuations mentioned above is that quantitative information on the vanadium salt used can only be made if the composition of the salt is known.
Wird nun ein Hydroxid der vorgegebenen Zusammensetzung einem Drehrohrofen zugeführt, und zwar in Anwesenheit der nach der Erfindung erforderlichen und als Mineralisator wirkenden Fluorverbindungen, insbesondere in Anwesenheit von 0,001 bis 0,1 Gew.-%, bezogen auf Al2O;, so erhält man bei Temperaturen oberhalb von 1100° C und sonst üblichen Ofeneinstellungen in Abhängigkeit von der Zelt ein weiteres Wachstum der mittleren Primärteilchengröße auf solche, die größer als 7 μπι, 10 μΐη, 12 μπι und 16 μπι sind und maximal 25 μπι sind. Die chemische Zusammensetzung der entstandenen Oxide zeigt einen Gehalt anIf a hydroxide of the specified composition is now fed to a rotary kiln, in the presence of the fluorine compounds required according to the invention and acting as mineralizers, in particular in the presence of 0.001 to 0.1% by weight, based on Al 2 O;, one obtains At temperatures above 1100 ° C and otherwise usual oven settings, depending on the tent, a further growth in the mean primary particle size to those which are greater than 7 μm, 10 μm, 12 μm and 16 μm and are a maximum of 25 μm. The chemical composition of the resulting oxides indicates a content
V2O5 von 0,005 bis 0,05 Gew.-%
P2O5 von 0,005 bis 0,05 Gew.-%
Na2O von 0,8 bis 3 Gew.-%V 2 O 5 from 0.005 to 0.05% by weight
P 2 O 5 from 0.005 to 0.05% by weight
Na 2 O from 0.8 to 3% by weight
Röntgenographisch existieren neben alpha-Al2O3 bedeutende Anteile an beta-Al2Oj, (z. B. Na2O · 11 Al2O3). Die Kalzinationstemperatur liegt bei dem neuen Verfahren zwischen 1100 und 1300° C.Radiographically, in addition to alpha-Al 2 O 3, there are significant proportions of beta-Al 2 Oj, (e.g. Na 2 O · 11 Al 2 O 3 ). The calcination temperature with the new process is between 1100 and 1300 ° C.
Die Dotierung des Ausgangshydrates mit dem Vanadinsalz kann technisch in einfacher Weise dadurch geschehen, daß das aus Natrlumaluminatlauge auskristallisierte Hydroxid bei der Filtration nur einer Teilwäsche unterzogen wird. Damit gelingt es, die für das Verfahren notwendigen Salze in der geforderten Größenordnung auf der Hydroxidoberfläche in feinst verteilter Form zu belassen. Mit einem so hergestellen filterfeuchten Hydroxid kann dann nach Zugabe der Fluorsalze, insbesondere in Mengen von 0,001-0,1 Gew.-%, bezogen auf Al2O3, ein grobkristallines Aluminiumoxid mit den für bestimmte Anwendungszwecke erforderlichen Eigenschaften hergestellt werden.The doping of the starting hydrate with the vanadium salt can be carried out in a technically simple manner in that the hydroxide which has crystallized out from sodium aluminate liquor is only partially washed during the filtration. This makes it possible to leave the salts required for the process in the required order of magnitude on the hydroxide surface in finely distributed form. With a filter-moist hydroxide produced in this way, after the addition of the fluorine salts, in particular in amounts of 0.001-0.1% by weight, based on Al 2 O 3 , a coarsely crystalline aluminum oxide with the properties required for certain applications can be produced.
Einem Drehrohrofen, der für die Herstellung eines bekannten Aluminiumoxids, hler einem Gemisch ausA rotary kiln, which is used for the production of a well-known aluminum oxide, hler a mixture of
s' gamma- und alpha-Al2O3, mit einer spezifischen Oberfläche von 5-30 mVg und einer mittleren Prlmärteilchen- s ' gamma- and alpha-Al 2 O 3 , with a specific surface area of 5-30 mVg and a mean primary particle
größe von ca. 1 μπι In Betrieb Ist, wird ein Hydroxid mit einer Dotierung von 0,01% V2O5, 0,01% P2O5, 0,02% F und von 1,2 Na2O sowie zusätzlich 0,02% AlF3, bezogen auf Al2O3, aufgegeben. Die Kalzinationstemperatur liegt bei ca. 12000C. Bereits nach 6 Stunden tritt ein starkes Kristallwachstum ein und nach 18-24 Stunden fällt ein Aluminiumoxid an, daß die für bestimmte Verwendungszwecke auf dem Schleif- und Pollergebiet erforderliche mittlere Primärkristallgröße von 12 μπι besitzt.size of approx. 1 μπι is in operation, a hydroxide with a doping of 0.01% V 2 O 5 , 0.01% P 2 O 5 , 0.02% F and 1.2 Na 2 O as well as additional 0.02% AlF 3 , based on Al 2 O 3 , abandoned. The calcination temperature is about 1200 ° C. Already after 6 hours there is strong crystal growth and after 18-24 hours an aluminum oxide is obtained that has the mean primary crystal size of 12 μm required for certain uses in the grinding and bollard area.
Ein Drehrohrofen, der für die Herstellung von alpha-Tonerde In Betrieb ist und dem zur schnelleren Umwandlung von Al(OH)3 in alpha-Al2O3 Aluminiumfluorld als Mlnerallsator in Mengen von 0,05% zugesetzt worden ist, erzeugt ein alpha-Al2O3 mit einer spezifischen Oberfläche von < 0,5 m2/g und eine mittlere Primärkrlstallgröße von ca. 5 μΐη. Nach Umstellung des Aufgabehydrates auf die Im Beispiel 1 angegebene erfindungsgemäße Dotierung produziert der Ofen nach ca. 10-12 Stunden bei sonst gleichen Ofenbedingungen ein Aluminiumoxid, daß die für bestimmte Verwendungszwecke notwendige mittlere Primärkristallgröße von ca. 10-16 μΐη besitzt. Die Temperatur des Ofens lag bei 1200° C.A rotary kiln, which is in operation for the production of alpha-alumina and to which aluminum fluoride has been added as a Mlnerallator in quantities of 0.05% for the faster conversion of Al (OH) 3 into alpha-Al 2 O 3, produces an alpha Al 2 O 3 with a specific surface of <0.5 m 2 / g and an average primary crystal size of approx. 5 μm. After changing the feed hydrate to the doping according to the invention specified in Example 1, the furnace produces after about 10-12 hours under otherwise identical furnace conditions an aluminum oxide that has the mean primary crystal size of about 10-16 μm necessary for certain uses. The temperature of the oven was 1200 ° C.
Claims (1)
0,005 bis 0,05 Gew.-% P2O5
0,8 bis 3 Gew.-% Na2O0.005 to 0.05 wt% V 2 O 5
0.005 to 0.05 wt% P 2 O 5
0.8 to 3 wt% Na 2 O
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE2623482A DE2623482C2 (en) | 1976-05-26 | 1976-05-26 | Process for the production of a crystalline aluminum oxide for polishing, lapping and grinding media |
| CA275,467A CA1084720A (en) | 1976-05-26 | 1977-04-04 | Method for production of coarse crystalline allumina |
| US05/800,046 US4130402A (en) | 1976-05-26 | 1977-05-24 | Method for producing coarsely crystalline alumina |
| JP52061695A JPS5812209B2 (en) | 1976-05-26 | 1977-05-26 | Coarse crystalline aluminum oxide and its manufacturing method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE2623482A DE2623482C2 (en) | 1976-05-26 | 1976-05-26 | Process for the production of a crystalline aluminum oxide for polishing, lapping and grinding media |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| DE2623482A1 DE2623482A1 (en) | 1977-12-08 |
| DE2623482C2 true DE2623482C2 (en) | 1985-06-27 |
Family
ID=5978984
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| DE2623482A Expired DE2623482C2 (en) | 1976-05-26 | 1976-05-26 | Process for the production of a crystalline aluminum oxide for polishing, lapping and grinding media |
Country Status (4)
| Country | Link |
|---|---|
| US (1) | US4130402A (en) |
| JP (1) | JPS5812209B2 (en) |
| CA (1) | CA1084720A (en) |
| DE (1) | DE2623482C2 (en) |
Families Citing this family (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2850064B1 (en) * | 1978-11-18 | 1980-05-08 | Giulini Chemie | Hexagonal tabular alpha alumina single crystals and process for their manufacture |
| CH654819A5 (en) * | 1980-09-23 | 1986-03-14 | Alusuisse | METHOD FOR PRODUCING COARSE CRYSTALLINE ALPHA ALUMINUM OXIDE AND THE USE THEREOF. |
| US4591383A (en) * | 1982-09-30 | 1986-05-27 | Corning Glass Works | Apparatus and method of filtering molten metal using honeycomb structure of sintered alumina as filter element |
| EP0107345B1 (en) * | 1982-09-30 | 1987-04-01 | Corning Glass Works | Improved alumina molten metal filters |
| US4568363A (en) * | 1985-03-08 | 1986-02-04 | Dresser Industries, Inc. | Method for making sintered aluminous abrasive particles |
| FR2652075B1 (en) * | 1989-09-21 | 1991-12-06 | Atochem | ALPHA ALUMINA MACROCRYSTALS IN THE FORM OF PLATES AND PROCESS FOR OBTAINING SAME. |
| US5296085A (en) * | 1989-09-21 | 1994-03-22 | Atochem | Macrocrystalline α-alumina hexagonal platelets |
| AU639326B2 (en) * | 1990-05-23 | 1993-07-22 | Atochem | Ceramic preforms comprising monocrystalline hexagonal platelets of alpha-alumina, their production and applications thereof |
| US5580673A (en) * | 1993-01-19 | 1996-12-03 | Energy Research Corporation | Carbonate fuel cell matrix |
| IL109236A (en) * | 1993-04-13 | 1998-01-04 | Sumitomo Chemical Co | Alpha-alumina powder and its production |
| DE69432451T2 (en) * | 1993-11-25 | 2004-03-11 | Sumitomo Chemical Co., Ltd. | Process for the production of alpha alumina powder |
| WO1995014638A1 (en) * | 1993-11-25 | 1995-06-01 | Sumitomo Chemical Company, Limited | PROCESS FOR PRODUCING α-ALUMINA POWDER |
| AU699077B2 (en) * | 1995-02-21 | 1998-11-19 | Sumitomo Chemical Company, Limited | Alpha-alumina and method for producing the same |
| US5869203A (en) * | 1996-12-13 | 1999-02-09 | Energy Research Corporation | Electrolyte matrix for molten carbonate fuel cells |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2360841A (en) * | 1944-10-24 | Aluminous material | ||
| CA678220A (en) * | 1964-01-14 | G. Lindsay James | Treatment of alumina | |
| GB1070659A (en) * | 1964-06-22 | 1967-06-01 | Alusuisse | Process for the purification of solutions containing soluble aluminates |
| US3406010A (en) * | 1965-09-08 | 1968-10-15 | Anaconda Co | Recovery of pure crystals of aici3.6h2o and production of aluminum oxide product therefrom |
| US3832442A (en) * | 1970-10-20 | 1974-08-27 | Kaiser Aluminium Chem Corp | Method for producing alumina hydrates |
| JPS4935990A (en) * | 1972-08-07 | 1974-04-03 | ||
| JPS4947405A (en) * | 1972-08-09 | 1974-05-08 | ||
| JPS5037806A (en) * | 1973-06-27 | 1975-04-08 |
-
1976
- 1976-05-26 DE DE2623482A patent/DE2623482C2/en not_active Expired
-
1977
- 1977-04-04 CA CA275,467A patent/CA1084720A/en not_active Expired
- 1977-05-24 US US05/800,046 patent/US4130402A/en not_active Expired - Lifetime
- 1977-05-26 JP JP52061695A patent/JPS5812209B2/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| CA1084720A (en) | 1980-09-02 |
| JPS5812209B2 (en) | 1983-03-07 |
| JPS5310400A (en) | 1978-01-30 |
| US4130402A (en) | 1978-12-19 |
| DE2623482A1 (en) | 1977-12-08 |
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